/*
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package eu.fastl.dragster.util;

public class PoiUtils {
    private static final String ALPHABETH = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    /**
     * generate the Excel colum name from the column index
     *
     * @param colNum
     *            the 0 based index of the column
     * @return the Name of the column as a String
     */
    public static String getColumnName(int colNum) {
        StringBuilder retval = new StringBuilder();
        if (colNum < 26) {
            retval.append(ALPHABETH.charAt(colNum));
        } else {
            int firstLetterIndex = (colNum / 26) - 1;
            int secondLetterIndex = colNum % 26;
            retval.append(ALPHABETH.charAt(firstLetterIndex));
            retval.append(ALPHABETH.charAt(secondLetterIndex));
        }
        return retval.toString();
    }
}
